misc: using move construct to avoid extra atomic inc/dec

Signed-off-by: Haomai Wang <haomai@xsky.com>

src/common/SloppyCRCMap.h

@@ -34,9 +34,7 @@ class SloppyCRCMap {
     //zero_crc = ceph_crc32c(0xffffffff, NULL, block_size);
     if (b) {
       bufferlist bl;
-      bufferptr bp(block_size);
-      bp.zero();
-      bl.append(bp);
+      bl.append_zero(block_size);
       zero_crc = bl.crc32c(crc_iv);
     } else {
       zero_crc = crc_iv;

src/erasure-code/ErasureCode.cc

@@ -93,12 +93,12 @@ int ErasureCode::encode_prepare(const bufferlist &raw,
 
     raw.copy((k - padded_chunks) * blocksize, remainder, buf.c_str());
     buf.zero(remainder, blocksize - remainder);
-    encoded[chunk_index(k-padded_chunks)].push_back(buf);
+    encoded[chunk_index(k-padded_chunks)].push_back(std::move(buf));
 
     for (unsigned int i = k - padded_chunks + 1; i < k; i++) {
       bufferptr buf(buffer::create_aligned(blocksize, SIMD_ALIGN));
       buf.zero();
-      encoded[chunk_index(i)].push_back(buf);
+      encoded[chunk_index(i)].push_back(std::move(buf));
     }
   }
   for (unsigned int i = k; i < k + m; i++) {

src/librbd/librbd.cc

@@ -968,7 +968,7 @@ namespace librbd {
     ImageCtx *ictx = (ImageCtx *)ctx;
     tracepoint(librbd, read_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(), ictx->read_only, ofs, len);
     bufferptr ptr(len);
-    bl.push_back(ptr);
+    bl.push_back(std::move(ptr));
     int r = ictx->aio_work_queue->read(ofs, len, bl.c_str(), 0);
     tracepoint(librbd, read_exit, r);
     return r;
@@ -980,7 +980,7 @@ namespace librbd {
     tracepoint(librbd, read2_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(),
 		ictx->read_only, ofs, len, op_flags);
     bufferptr ptr(len);
-    bl.push_back(ptr);
+    bl.push_back(std::move(ptr));
     int r = ictx->aio_work_queue->read(ofs, len, bl.c_str(), op_flags);
     tracepoint(librbd, read_exit, r);
     return r;

src/msg/async/AsyncConnection.cc

@@ -161,19 +161,16 @@ static void alloc_aligned_buffer(bufferlist& data, unsigned len, unsigned off)
     // head
     unsigned head = 0;
     head = MIN(CEPH_PAGE_SIZE - (off & ~CEPH_PAGE_MASK), left);
-    bufferptr bp = buffer::create(head);
-    data.push_back(bp);
+    data.push_back(buffer::create(head));
     left -= head;
   }
   unsigned middle = left & CEPH_PAGE_MASK;
   if (middle > 0) {
-    bufferptr bp = buffer::create_page_aligned(middle);
-    data.push_back(bp);
+    data.push_back(buffer::create_page_aligned(middle));
     left -= middle;
   }
   if (left) {
-    bufferptr bp = buffer::create(left);
-    data.push_back(bp);
+    data.push_back(buffer::create(left));
   }
 }
 
@@ -727,10 +724,9 @@ void AsyncConnection::process()
           // read front
           unsigned front_len = current_header.front_len;
           if (front_len) {
-            if (!front.length()) {
-              bufferptr ptr = buffer::create(front_len);
-              front.push_back(ptr);
-            }
+            if (!front.length())
+              front.push_back(buffer::create(front_len));
+
             r = read_until(front_len, front.c_str());
             if (r < 0) {
               ldout(async_msgr->cct, 1) << __func__ << " read message front failed" << dendl;
@@ -750,10 +746,9 @@ void AsyncConnection::process()
           // read middle
           unsigned middle_len = current_header.middle_len;
           if (middle_len) {
-            if (!middle.length()) {
-              bufferptr ptr = buffer::create(middle_len);
-              middle.push_back(ptr);
-            }
+            if (!middle.length())
+              middle.push_back(buffer::create(middle_len));
+
             r = read_until(middle_len, middle.c_str());
             if (r < 0) {
               ldout(async_msgr->cct, 1) << __func__ << " read message middle failed" << dendl;

src/msg/simple/Pipe.cc

@@ -333,7 +333,7 @@ int Pipe::accept()
   }
   {
     bufferptr tp(sizeof(peer_addr));
-    addrbl.push_back(tp);
+    addrbl.push_back(std::move(tp));
   }
   if (tcp_read(addrbl.c_str(), addrbl.length()) < 0) {
     ldout(msgr->cct,10) << "accept couldn't read peer_addr" << dendl;
@@ -371,7 +371,7 @@ int Pipe::accept()
         ldout(msgr->cct,10) << "accept couldn't read connect authorizer" << dendl;
         goto fail_unlocked;
       }
-      authorizer.push_back(bp);
+      authorizer.push_back(std::move(bp));
       authorizer_reply.clear();
     }
 
@@ -948,7 +948,7 @@ int Pipe::connect()
     int wirelen = sizeof(__u32) * 2 + sizeof(ceph_sockaddr_storage);
     bufferptr p(wirelen * 2);
 #endif
-    addrbl.push_back(p);
+    addrbl.push_back(std::move(p));
   }
   if (tcp_read(addrbl.c_str(), addrbl.length()) < 0) {
     ldout(msgr->cct,2) << "connect couldn't read peer addrs, " << cpp_strerror(errno) << dendl;
@@ -1876,19 +1876,16 @@ static void alloc_aligned_buffer(bufferlist& data, unsigned len, unsigned off)
     // head
     unsigned head = 0;
     head = MIN(CEPH_PAGE_SIZE - (off & ~CEPH_PAGE_MASK), left);
-    bufferptr bp = buffer::create(head);
-    data.push_back(bp);
+    data.push_back(buffer::create(head));
     left -= head;
   }
   unsigned middle = left & CEPH_PAGE_MASK;
   if (middle > 0) {
-    bufferptr bp = buffer::create_page_aligned(middle);
-    data.push_back(bp);
+    data.push_back(buffer::create_page_aligned(middle));
     left -= middle;
   }
   if (left) {
-    bufferptr bp = buffer::create(left);
-    data.push_back(bp);
+    data.push_back(buffer::create(left));
   }
 }
 
@@ -1976,7 +1973,7 @@ int Pipe::read_message(Message **pm, AuthSessionHandler* auth_handler)
     bufferptr bp = buffer::create(front_len);
     if (tcp_read(bp.c_str(), front_len) < 0)
       goto out_dethrottle;
-    front.push_back(bp);
+    front.push_back(std::move(bp));
     ldout(msgr->cct,20) << "reader got front " << front.length() << dendl;
   }
 
@@ -1986,7 +1983,7 @@ int Pipe::read_message(Message **pm, AuthSessionHandler* auth_handler)
     bufferptr bp = buffer::create(middle_len);
     if (tcp_read(bp.c_str(), middle_len) < 0)
       goto out_dethrottle;
-    middle.push_back(bp);
+    middle.push_back(std::move(bp));
     ldout(msgr->cct,20) << "reader got middle " << middle.length() << dendl;
   }
 

src/os/FuseStore.cc

@@ -809,9 +809,7 @@ static int os_write(const char *path, const char *buf, size_t size,
     } else {
       final.claim_append(*pbl);
       size_t zlen = offset - final.length();
-      bufferptr z(zlen);
-      z.zero();
-      final.append(z);
+      final.append_zero(zlen);
     }
   }
   final.append(buf, size);

src/os/bluestore/BlueFS.cc

@@ -304,9 +304,7 @@ int BlueFS::_write_super()
   uint32_t crc = bl.crc32c(-1);
   ::encode(crc, bl);
   assert(bl.length() <= get_super_length());
-  bufferptr z(get_super_length() - bl.length());
-  z.zero();
-  bl.append(z);
+  bl.append_zero(get_super_length() - bl.length());
   bl.rebuild();
 
   IOContext ioc(NULL);
@@ -889,12 +887,8 @@ void BlueFS::_pad_bl(bufferlist& bl)
 {
   uint64_t partial = bl.length() % super.block_size;
   if (partial) {
-    bufferptr z(super.block_size - partial);
-    dout(10) << __func__ << " padding with " << z.length() << " zeros" << dendl;
-    z.zero();
-    bufferlist zbl;
-    zbl.append(z);
-    bl.append(z);
+    dout(10) << __func__ << " padding with " << super.block_size - partial << " zeros" << dendl;
+    bl.append_zero(super.block_size - partial);
   }
 }
 
@@ -1038,9 +1032,7 @@ int BlueFS::_flush_range(FileWriter *h, uint64_t offset, uint64_t length)
       dout(20) << __func__ << " caching tail of " << tail
 	       << " and padding block with zeros" << dendl;
       h->tail_block.substr_of(bl, bl.length() - tail, tail);
-      bufferptr z(super.block_size - tail);
-      z.zero();
-      t.append(z);
+      t.append_zero(super.block_size - tail);
     }
     bdev[p->bdev]->aio_write(p->offset + x_off, t, h->iocv[p->bdev], true);
     bloff += x_len;

src/os/bluestore/BlueStore.cc

@@ -841,7 +841,7 @@ int BlueStore::_write_bdev_label(string path, bluestore_bdev_label_t label)
   assert(bl.length() <= BDEV_LABEL_BLOCK_SIZE);
   bufferptr z(BDEV_LABEL_BLOCK_SIZE - bl.length());
   z.zero();
-  bl.append(z);
+  bl.append(std::move(z));
 
   int fd = ::open(path.c_str(), O_WRONLY);
   if (fd < 0) {
@@ -2552,9 +2552,7 @@ int BlueStore::_do_read(
 	// unwritten (zero) extent
 	dout(30) << __func__ << " data " << bp->first << ": " << bp->second
 		 << ", use " << x_len << " zeros" << dendl;
-	bufferptr bp(x_len);
-	bp.zero();
-	bl.push_back(bp);
+	bl.append_zero(x_len);
       }
       offset += x_len;
       length -= x_len;
@@ -2571,9 +2569,7 @@ int BlueStore::_do_read(
 
     // zero.
     dout(30) << __func__ << " zero " << offset << "~" << x_len << dendl;
-    bufferptr bp(x_len);
-    bp.zero();
-    bl.push_back(bp);
+    bl.append_zero(x_len);
     offset += x_len;
     length -= x_len;
     continue;
@@ -5473,10 +5469,8 @@ int BlueStore::_do_write_zero(
   uint64_t offset,
   uint64_t length)
 {
-  bufferptr z(length);
-  z.zero();
   bufferlist zl;
-  zl.push_back(z);
+  zl.append_zero(length);
   return _do_write(txc, c, o, offset, length, zl, 0);
 }
 

src/os/filestore/FileJournal.cc

@@ -766,7 +766,7 @@ int FileJournal::read_header(header_t *hdr) const
       memset(bpdata, 0, bp.length() - r);
   }
 
-  bl.push_back(bp);
+  bl.push_back(std::move(bp));
 
   try {
     bufferlist::iterator p = bl.begin();
@@ -1885,7 +1885,7 @@ void FileJournal::wrap_read_bl(
 	   << r << dendl;
       ceph_abort();
     }
-    bl->push_back(bp);
+    bl->push_back(std::move(bp));
     pos += len;
     olen -= len;
   }

src/os/filestore/FileStore.cc

@@ -1164,7 +1164,7 @@ int FileStore::read_superblock()
   }
 
   bufferlist bl;
-  bl.push_back(bp);
+  bl.push_back(std::move(bp));
   bufferlist::iterator i = bl.begin();
   ::decode(superblock, i);
   return 0;
@@ -1186,7 +1186,7 @@ int FileStore::version_stamp_is_valid(uint32_t *version)
     return ret;
   }
   bufferlist bl;
-  bl.push_back(bp);
+  bl.push_back(std::move(bp));
   bufferlist::iterator i = bl.begin();
   ::decode(*version, i);
   dout(10) << __func__ << " was " << *version << " vs target "
@@ -2969,7 +2969,7 @@ int FileStore::read(
     return got;
   }
   bptr.set_length(got);   // properly size the buffer
-  bl.push_back(bptr);   // put it in the target bufferlist
+  bl.push_back(std::move(bptr));   // put it in the target bufferlist
 
 #ifdef HAVE_POSIX_FADVISE
   if (op_flags & CEPH_OSD_OP_FLAG_FADVISE_DONTNEED)
@@ -3278,10 +3278,8 @@ int FileStore::_zero(const coll_t& cid, const ghobject_t& oid, uint64_t offset,
   // write zeros.. yuck!
   dout(20) << "zero FALLOC_FL_PUNCH_HOLE not supported, falling back to writing zeros" << dendl;
   {
-    bufferptr bp(len);
-    bp.zero();
     bufferlist bl;
-    bl.push_back(bp);
+    bl.append_zero(len);
     ret = _write(cid, oid, offset, len, bl);
   }
 
@@ -4421,7 +4419,7 @@ int FileStore::collection_getattr(const coll_t& c, const char *name, bufferlist&
     goto out;
   }
   r = _fgetattr(fd, n, bp);
-  bl.push_back(bp);
+  bl.push_back(std::move(bp));
   VOID_TEMP_FAILURE_RETRY(::close(fd));
  out:
   dout(10) << "collection_getattr " << fn << " '" << name << "' = " << r << dendl;

src/os/filestore/GenericFileStoreBackend.cc

@@ -344,7 +344,7 @@ int GenericFileStoreBackend::_crc_load_or_init(int fd, SloppyCRCMap *cm)
     }
   }
   bufferlist bl;
-  bl.append(bp);
+  bl.append(std::move(bp));
   bufferlist::iterator p = bl.begin();
   try {
     ::decode(*cm, p);

src/os/fs/FS.cc

@@ -170,9 +170,7 @@ int FS::zero(int fd, uint64_t offset, uint64_t length)
   {
     // fall back to writing zeros
     bufferlist bl;
-    bufferptr bp(length);
-    bp.zero();
-    bl.append(bp);
+    bl.append_zero(length);
     r = ::lseek64(fd, offset, SEEK_SET);
     if (r < 0) {
       r = -errno;

src/os/fs/FS.h

@@ -75,8 +75,7 @@ class FS {
     void pread(uint64_t _offset, uint64_t len) {
       offset = _offset;
       length = len;
-      bufferptr p = buffer::create_page_aligned(length);
-      bl.append(p);
+      bl.append(buffer::create_page_aligned(length));
       io_prep_pread(&iocb, fd, p.c_str(), length, offset);
     }